CHANGES OF EXPRESSION LEVELS OF CHOLINE-ACETYLTRANSFERASE AND VESICULAR ACETYLCHOLINE TRANSPORTER MESSENGER-RNAS AFTER TRANSECTION OF THE HYPOGLOSSAL NERVE IN ADULT RATS

Acetylcholine, synthesized in the cytoplasm of cholinergic neurons by choline acetyltransferase (ChAT), is packaged in synaptic vesicles by vesicular acetylcholine transporter (VAChT). The entire VAChT gene has been reported to be located within the first intron of the ChAT gene. in order to examine whether or not ChAT and VAChT transcription may b e coordinately regulated, the levels of ChAT and VAChT mRNAs in hypogl ossal neurons were analyzed by in situ hybridization following transec tion of the hypoglossal nerve in adult rats. After unilateral transect ion, the levels of expression of ChAT and VAChT mRNAs were dramaticall y reduced in the ipsilateral hypoglossal nucleus 1 week after the surg ery. However the expression of both mRNAs gradually recovered thereaft er. These results suggest that the transcription of the two cholinergi c genes is tightly linked in motor neurons. (C) 1997 Elsevier Science Ireland Ltd.